rebellance24, the Sims franchise has always been a single-player experience. My own kids play it, but we would never want to play co-op. We each enjoy our own saves snd do not want anyone "joining" it. When my family games together, we actually can play 4 different games in the same room (I have 2 EA accounts so we can have 2 people play Sims 4 if we want). I actually do not know anyone IRL who would wants to co-op in The Sims. I started playing the franchise since the Sims 1 days in the early 2000's. I have never owned a console Sims game.
If you look up the history about Sims 4, look up project Olympus. It was rumored to orginally have an online playing experience, but that was scraped when the Sim City always online requirement got backlash. It is why all the sims act so similarly, no matter what traits they are given and why the game can feel so repetitive. There are too many different pack combinations for any online multi-player to work, that isn't even considering if PC players use CC.